Apparatus for drying sheet material



Nov. 12, 1957 w. H. LAMASON APPARATUS FOR DRYING SHEET MATERIAL 2 Sheets-Sheet 1 Filed July 28. 1954 Nov. 12, 1957 w. H. LAMASON APPARATUS FOR DRYING SHEET MATERIAL 2 Sheets-Sheet 2 Filed July 28, 1954 United States Patent O APPARATUS FOR DRYING SHEET 'MATERIAL William H. Lamason, Fredericksburg, Va., assignor to American Viscose Corporation, Philadelphia, Pa., a corporation of Delaware Application July 28, 1954, Serial No. 446,228

4 Claims. (Cl. 34-421) The present invention relates to an apparatus for drying flexible sheet material and more particularly to an apparatus for simultaneously drying a plurality of continuous cellophane sheets.

In order to meet growing demands by consumers for cellophane, the cellophane manufacturers have had to double or even triple their production. This demand has been met by producing two or three continuous sheets of cellophane on multiple sheet spinning machines. Multiple sheet drying methods and apparatus were designed to handle the plurality of sheets produced on the multiple casting or (Spinning) machines. One of these multiple drying systems included an upper and lower set of drying rolls through which the sheets were passed in superimposed relationship. The sheets were separated at various steps along their path through the drying rolls to assure uniform drying throughout the sheet thickness. The main disadvantage with such a system is that the film surfaces are somewhat damaged due to their coming into and out of contact with each other while in their wet state. The initial threading of the films through such drying apparatus was somewhat complicated in that the wet films had to be separated at various stations along their path which resulted in frequent tearing of the films. Another system provided a separate drying apparatus, such as that used originally for drying the single continuous sheet, for each sheet issuing from the casting or spinning apparatus. The advantages of such a system are greatly diminished due to the tremendous amount of space required to house two or three of these cumbersome drying units.

It is therefore an object of the present invention to provide an apparatus for simultaneously drying a plurality of cellophane sheets whereby such disadvantages listed above are eliminated.

It is an object of the invention to provide an apparatus for drying a plurality of continuously traveling sheets of flexible material wherein one sheet is passed through an upper set of drying rolls and a second sheet is passed through a lower set of drying rolls whereby the sheets are maintained in a separated condition during their travel through the system to assure uniform and thorough sheet drying.

It is also an object of the invention to provide an apparatus for drying a plurality of traveling sheets of flexible material which apparatus occupies a minimum of space and wherein the films may be initially threaded through the system in a non-complex manner without the danger of tearing or damaging.

It is a further object of the invention to provide a separate driving system for an upper and lower set of drying rolls wherein the speed of one set may be corre lated through a dual control unit with the speed of the other set.

For a more complete understanding of the invention reference is made to the following description and drawing in which:

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Figure 1 is a schematic side view of the apparatus, a portion of which is broken away,

Figure 2 is an enlarged side view of the apparatus, a portion of which is broken away and which shows the wet and dry ends of the dryer system and the driving means for the drying rolls,

Figure 3 is an enlarged partially sectioned view taken along lines Ill-III of Figure 1,

Figure 4 is an enlarged fragmentary top view of the dry end of the apparatus,

Figure 5 is a detail showing the path of the cellophane sheets over the drying roll-s and,

Figure 6 is a view of reduced scale taken along lines VI-VI of Figure 2. l

In general the present invention comprises feeding a plurality of wet continuous sheets such as cellophane in separated condition to a roll drying system wherein one sheet follows an over and under path through a bottom set of drying rolls while the other sheet follows a similar path through an upper set of drying rolls. A separate sprocket and chain system is provided for driving each set of rolls wherein the drive sprockets of each system are connected with an external dual drive unit in such a manner that the speed of the two systems may be correlated. A chain return trough supports and guides the chains of each system during their return travel from the dry end to the wet end of the system.

Referring now to the drawings, especially Figs. 1 and 2, my improved drier comprises an upper set of rotatable drying rolls 1, 1 and a lower set of drying rolls or drums 2, 2 mounted on a support 3 which may be affixed to the floor or a platform. The hollow rolls 1, 1 and 2, 2 may be heated by introducing steam or other heating medium thereinto. These rolls receive the cellophane films 4 and 5, or other type flexible sheet material, as they emerge from the final treating bath of the spinning or casting apparatus. As seen in Fig. 5, film 4 passes through the upper set of drying rolls 1, 1 in an over and under manner while film 5 passes over the lower set of drying rolls 2, 2 in similar fashion. Chain 6 (Figs. 1 and 2) cooperates with sprockets 8, 8 affixed to one end of each of the upper rolls 1, 1 and chain 7 cooperates with sprockets 9, 9 affixed to one end of each of the lower rolls 2, 2 to drive the rolls. Chain drive sprockets 10 and 11 positioned beneath the upper and lower drying rolls at the wet end of the drying apparatus drive the chains 7 and 6 respectively. The drive sprockets 10 and 11 are driven through shafts 10a and 11a journalled in bearings F. F. and connected with driving motor M (Figure 6). Shaft 11a is connected with motor M through clutch 1112 while shaft 10a is connected with motor M through clutch 10!) through a variable speed drive or reeves drive B connecting shaft 10a with shaft 11a. The speed of the upper drying rolls may be easily adjusted as desired or correlated with the speed of the lower rolls merely by proper adjustment of the reeves drive unit B. During the initial threading of the sheets through the rolls, it may be desirable to operate only one set of rolls at a time. With the present driving system this may be accomplished by merely disengaging the clutch 10b or clutch 11b for the drive sprockets 10 and 11 as desired.

As seen in Figs. 1, 2, and 5 the film 4 follows the same over and under path through the drying rolls 1, 1 as does the chain 6. The same is true for film 5 and chain 7. With such an arrangement, adjacent rolls of each deck rotate in opposite directions so that the sheets 4 and 5 are positively passed from the wet end of the dryer to its dry end.

Tension is maintained upon chains 6 and 7 by tension sprockets 12, 12 positioned beneath the drying rolls preferably at the dry end of the system. The tension sprockets 12, 12', see Figs. 1, 2, and 4, are mounted on shafts 13, 13 which shafts are supported by upright arms 14, 14' and in turn afiixed to the ends of horizontally positioned shafts 15, 15'. The shafts 15, 15 are journalled in bearings 16, 16 and 16', 16, affixed to frame 3. Weighted arms 17, 17 secured to the opposite ends of shafts 15, 15 and extending in a horizontal plane therefrom urge the tension sprockets 12, 12 into contact with chains 6 and 7.

Sprockets 18, 13' and 19, 19 guide the chains 6 and 7 to a chain trough support asssembly Z positioned below the drying rolls 1, 1 and 2, 2 and between tension sprockets 12, 12 and drive sprockets 10 and 11, Figures 1 and 2. The trough assembly 20 afiixed to frame 3 supports the chains 6 and 7 during their travel from the dry end of the drying system to the wet end. The trough assembly 20 comprises an upper trough 21 and a lower trough 21, see Fig. 3, which troughs accommodate chains 7 and 6 respectively. As the chains 6 and 7 emerge from the opposite end of trough assembly 20 they pass over guide sprockets 22, 22' and then around drive sprockets 11 and 10 respectively. From this point the chains 6 and 7 pass upwardly to sprockets 8, 8 and 9, 9 affixed to the upper and lower drying rolls 1, 1 and 2, 2.

In operation, the top film 4 is fed to the top set of rolls 1, 1 by passing over the first roll in the series, under the second roll and over the third roll, and so on. The driving chain 6 follows the rolls 1, 1 in the same manner. Film and chain '7 assume similar paths of travel with respect to the lower set of rolls 2, 2. Should it be necessary to adjust or to correlate the speed of the top rolls with that of the bottom rolls, the reeves drive affixed to the drive shaft for the top rolls may be ad justed as required to increase or decrease the speed of the top rolls.

Since various modifications may be made in practicing the invention without departing from the spirit and scope thereof, it is to be understood that the invention is not to be limited to the specific embodiments herein defined in the appended claims.

I claim:

1. Apparatus for drying a plurality of continuously traveling sheets of flexible material comprising a frame, an upper deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a lower deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a separate sprocket and chain drive system for each roll deck, and chain supporting and guiding means positioned below the drying roll decks for supporting the chains during their travel from the dry end of the apparatus to the wet end thereof.

2. Apparatus for drying a plurality of continuously traveling sheets of flexible material comprising a frame, an upper deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a lower deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a separate sprocket and chain drive system for each roll deck, and a chain supporting trough positioned below the drying roll decks for supporting the chains during their travel from the dry end of the apparatus to the wet end thereof.

3. Apparatus for drying a plurality of continuously traveling sheets according to claim 2 wherein the chain supporting trough is partitioned into an upper trough and a lower trough for supporting the chains individually during their return to the wet end of the drying system.

4. Apparatus for drying a plurality of continuously traveling sheets of flexible material comprising a frame, an upper deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a lower deck of drying rolls rotatably mounted in the same horizontal plane on the frame, a separate sprocket and chain driving system for each roll deck, a drive unit connected with one of the sprocket and chain driving systems, adjustable means connecting said drive unit with the other chain and sprocket system whereby the rate of rotation of said other chain and sprocket system may be adjusted as desired, and a chain supporting trough positioned below the drying roll decks for supporting the chains during their travel from the dry end of the apparatus to the wet end thereof.

References Cited in the file of this patent UNITED STATES PATENTS 829,686 Barber Aug. 28, 1906 1,407,154 Headson Feb. 21, 1922 1,663,237 Berry Mar. 20, 1928 1,787,520 Hampel Jan. 6, 1931 2,438,084 Wood Mar. 16, 1948 FOREIGN PATENTS 328,566 Great Britain Apr. 28, 1930 

